American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Mar 2023
Editorial CommentCancer or Not Cancer: That Is the Question.
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Am. J. Respir. Crit. Care Med. · Mar 2023
Positive- and Negative-Pressure Ventilation Characterized by Local and Global Pulmonary Mechanics.
Rationale: There is continued debate regarding the equivalency of positive-pressure ventilation (PPV) and negative-pressure ventilation (NPV). Resolving this question is important because of the different practical ramifications of the two paradigms. Objectives: We sought to investigate the parallel between PPV and NPV and determine whether or not these two paradigms cause identical ventilation profiles by analyzing the local strain mechanics when the global tidal volume (Vt) and inflation pressure was matched. ⋯ Conclusions: Apparently, contradictory previous studies are not mutually exclusive. Equivalent changes in transpulmonary pressures in PPV and NPV lead to the same changes in lung volume and pressures, yet local tissue strains differ between PPV and NPV. Although limited to healthy specimens and ex vivo experiments in the absence of a chest cavity, these results may explain previous reports of better oxygenation and less lung injury in NPV.